Using Cycles renderer the reflections look good in viewport but not in in the render, why is this happening?
The issue is not the reflections, but the fact that they are blocked by something else. It looks like you have another object on top that is not visible in the 3d viewport but is renderable.
Those three big squares that are overlaid on the ground most likely belong to such object.
In the outliner search for objects that have been disabled for view (eye icon) but have the camera icon enabled. The camera icon determines if the object renders or not.